Reapers, machines developed in the early 1800s to help farmers harvest grain such as wheat, dramatically increased overall grain production and consumption in the United States and the rest of the world. The first commercially successful reaper was built in 1831 by Virginia-born inventor Cyrus Hall McCormick (1809–1884), who patented it in 1834 and first sold it in 1840 in Virginia. The McCormick reaper was horse-drawn and replaced the use of sickles and scythes in the fields; it also reduced the amount of manual labor required to harvest grain crops. It worked in this way: A straight blade (protected by guards) was linked to a drive wheel; as the drive wheel turned, the blade moved back and forth in a sawing motion, cutting through the stalks of grain, which were held straight by rods; the cut grain stalks then fell onto a platform and were collected with a rake by a worker. The device increased average production from two or three acres a day to ten acres a day. McCormick’s reaper was soon in wide use, and the inventor was on his way to becoming an industrialist.

In 1847 he moved his business to Chicago, were he could transport reapers via the Great Lakes and connected waterways to the East and to the South. Within five years McCormick’s business had become the largest farm implement factory in the world. Sales and distribution of the equipment increased further during the 1850s as Chicago became a center for the nation’s then-expanding rail system. In 1879 Cyrus McCormick’s business became the McCormick Harvesting Machine Company, with the inventor himself as president (until 1884, when he was succeeded by his son). The reaper was improved over time: in the 1850s a self-raking feature was added, further reducing the amount of labor required to harvest grain; in the 1870s a binder was added, which bound the sheaves of grain and dropped them to the ground to be collected. In the 1920s the reaper (or harvester) was joined with another invention, the thresher, which separates grains from the stalks. The new reaper-thresher machine was called a combine. Today’s combines still use the basic features present in McCormick’s revolutionary 1831 invention. His company later became International Harvester (1902) and today is known as Navistar Corporation.